The present invention relates to the field of data transfer. More specifically, the present invention relates to transferring data between disparate capacity database systems.
A database system is a collection of information organized in such a way that data may be accessed quickly. Database applications are present in everyday use including automated teller machines, flight reservation systems, and internet-account systems of all types. A database management system (DBMS) is a collection of programs that allow the entry, modification, and selection of data in a database. There are various types of DBMSs, ranging from small systems that run on personal computers to larger systems that run on mainframe systems.
Requests for information from a database are made by a database server using a query language. Different DBMSs support different query languages, including a standardized language called xe2x80x9cstructured query languagexe2x80x9d (SQL), for example. Database servers that use SQL are often referred to as xe2x80x9cSQL servers.xe2x80x9d SQL supports distributed database systems, which are databases that are spread out over several server systems, yet act as one. A distributed database system must replicate and synchronize data among its many databases. In this way, a distributed database system may enable several users on a network to access the same database simultaneously without interfering with one another. Therefore, a distributed database system may have many SQL servers located in various locations, each responsible for certain portions of the database""s overall operation.
In distributed database systems often there occurs a disparity in the relative capacity to perform work among the individual databases in the system. This can happen for a variety of reasons, including but not limited to new demand conditions, addition of newer hardware in one subsystem which is substantially faster than the legacy systems, and progressive redesign and redeployment of portions of an existing system. Moreover, it may be more efficient to gain the functionality of a new distributed database by dividing the database""s operation between a newer and faster database server and the legacy server. In either case, the result is that various versions of database servers simultaneously may exist in one database system.
Although having multiple versions of SQL servers in one database system may be more cost efficient, often this scenario causes technical concerns. This is particularly true, for example, where a database system is designed to allow a faster upgraded database server to automatically transact with a slower legacy database that may be in various states of repair. In this instance, transactions may be received from the upgraded server at a rate faster than the legacy server can process them. This disparate capacity is particularly troubling in a distributed database system where the overwhelming rate of transactions entering the legacy system may break down the replication process and return corrupted or stale data to the upgraded server.
To date, when confronted with these disparate server systems, administrators are forced to upgrade the slower legacy system to be compatible with the faster upgraded system. Therefore, there exists a need to regulate incoming transactions from the upgraded server to a rate that is compatible with the slower legacy server.
In many computer systems, the rate of data from an input source may become significantly faster than a processor""s ability to respond. This situation occurs, for example, when a faster and more modern system writes to an older and slower legacy system. Such interactions between disparate capacity systems may result in failure or data corruption, particularly due to overloading the slower system""s input queue to the point where it can no longer catch up to its workload. For example, in a database computer system, when the rate of incoming transactions from an updated database system exceeds a smaller capacity database system""s ability to process transactions, system failure may occur. In some instances when this situation arises, system administrators may upgrade the legacy database system to operate with the updated database system. In running production systems, this is often operationally unfeasible, or not feasible in a reasonable time frame. Where system upgrade is impossible or unfeasible, there exists a need to slow incoming transactions down to a rate compatible with the slower legacy system.
The invention provides a method, system, and computer-readable medium having computer-executable instructions for transferring data between disparate capacity systems. The method comprises the steps of receiving transactions from a first computer system at a first rate and providing the transactions to a second computer system, wherein the second computer system receives the transactions at a second rate. The second computer system may be a database legacy database server and the first computer system may be an updated database server The second rate is set at a capacity of the second computer system. The method further delays for a predetermined period of time the transactions when the first rate exceeds the second rate. The predetermined period of time is a function of the second rate.